Pigeon cause bridge collapse
I am sure many of you have heard of the terrible collapse of the I35 bridge collapse in Minnesota. Well, my girlfriend used to go to college up there, and I drove over that bridge many times. I have been following the coverage of this collapse, and recently heard that they are blaming it on "pigeon dung". I guess it's very acidic and can rust bolts and eat through metal. Supposedly the pigeon dung was reported many times, but nothing was really done about it. I thought this was really quite interesting.
